There was a question posed on MyBBCentral about how you would go about forcing users to have lowercase usernames. I had a quick look at the core files and found a way of doing it that I thought I would share in case anybody else wanted it.

First of all, we're going to need to edit the member.php core file. Open it up in your favorite editor (I recommend notepad++ for a plain text eitor or Aptana Studio as an IDE).

Find:

Replace with:

This edit will change all registered usernames to be lowercase after the registration form has been submitted.

I have tested this a fair bit locally in both 1.4.13 and 1.6 BETA so all should be fine

So it chances to lowercase letter, even if they submitted something like DaSpamBot,(-> daspambot).
Without any message or something ?, unless you add a text line yourself.

Yup. That's basically what it does You could probably add some kind of notification using an if statement (like if $new = $old { } else { print "your name has been changed"; }; )

I don't think i'd be using this, but if i would i would add a text line above the username bar notifying that uppercase will be set to lowercase.

Once again thanks for this great share which is pure simplicity to use !.

I am thinking about this for my forum, But I am not sure weather it will cause people to leave :S

Yah some usernames are really Messy(Not that Argentina One ).Is there something which will forbid users to enter symbols and special chars?

I'm sure there would be a way by preg_replacing the symbols and special chars, but I can't really think of one atm. I'll have a play with it.

Is there a code to make all caps changed? Like username hElLo would not be banned but HELLO would?

very good guide.